Touch processing device and method thereof

ABSTRACT

The present invention provides a touch processing device which is configured to connect to a touch sensitive panel having a plurality of sensing points. The touch processing device comprises a transmitter detecting module and an information transmitting module. The transmitter detecting module is configured to detect a transmitter transmitting an electrical signal only when approaching or touching the touch sensitive panel and to generate at least a two-dimensional sensing information. The at least one two-dimensional sensing information is sensing information corresponding to the plurality of sensing points with respect to at least one frequency. The information transmitting module is configured to transmit the at least one two-dimensional sensing information.

CROSS REFERENCE TO RELATED APPLICATIONS

This present invention is a continuation application of U.S. patentapplication Ser. No. 14/537,211, filed on Nov. 10, 2014.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to touch processing devices and moreparticularly, to touch processing devices capable of transmitting aplurality of detection images.

2. Description of the Prior Art

Touch sensitive panels or screens are important human-machineinterfaces, especially for consumer electronic products like portablephones, tablet PCs, or Personal Digital Assistances (PDAs). Touchsensitive screens are one of the main input/output (I/O) devices. Ascapacitive touch sensitive screens, especially those of projectedcapacitive types, are highly sensitive to finger touches, it has becomeone of the main design choices for touch sensitive panels/screens on themarket. Touching the screen with the tip of a finger will inevitablyblock part of the screen, and the user will not be able to visuallyconfirm a point that is being detected by the touch sensitive. Inaddition, one cannot have as accurate control as using a pen (or stylus)when using their finger tip(s) to write. Therefore, in addition to usingfinger tips for touch control, users may also wish to use a stylus forinput to the screen.

Generally, the area on a touch sensitive screen touched by the tip of astylus is much smaller than that touched by the fingertips. Forcapacitive touch sensitive screens, it has been a challenge to detectthe capacitive changes caused by a stylus. In particular, in manyprofessional graphics or typesetting application environments, a lot offunctional buttons needs to be added in the design process of thestylus. In view of this demand, the touch sensitive screen not onlyneeds to detect the tiny tip of the stylus, but also needs to determinewhether these buttons are being pressed.

Since there may be more than one kind of objects, such as the tip of apen, a finger, a palm etc., simultaneously present on the touchsensitive screen, the touch processing devices may need to employ aplurality of sensing methods for sensing the same touch sensitivepanel/screen in order to distinguish the different kinds of objectapproaching or touching the touch sensitive panel/screen.

In summary, there is a need on the market for a touch processing devicethat is not only capable of providing sensing information regarding astylus, but also capable of transmitting capacitively sensed sensinginformation to allow a receiving end to generate more than one kind ofimages with the same touch sensitive panel for subsequent processing.

SUMMARY OF THE INVENTION

In an embodiment, the present invention provides a touch processingdevice connected to a touch sensitive panel with a plurality of sensingpoints. The touch processing device may include a transmitter detectingmodule and an information transmitting module. The transmitter detectingmodule is configured to detect a transmitter that transmits anelectrical signal only when approaching or touching the touch sensitivepanel, and generate at least one two-dimensional (2D) sensinginformation, wherein the at least one 2D sensing information is asensing information corresponding to a plurality of sensing points withrespect to at least one frequency. The information transmitting moduleis configured to transmit the at least one 2D sensing information.

In another embodiment, the present invention provides a touch processingmethod applicable to a touch processing device connected to a touchsensitive panel having a plurality of sensing pints. The method mayinclude detecting a transmitter that transmits an electrical signal onlywhen approaching or touching the touch sensitive panel, and generatingat least one two-dimensional (2D) sensing information, wherein the atleast one 2D sensing information is a sensing information correspondingto the plurality of sensing points with respect to at least onefrequency; and transmitting the at least one 2D sensing information.

In summary, one of the main principles of the present invention lies inthat the touch processing device is capable of providing sensinginformation with respect to various frequencies as well as optionalcapacitive sensing information to allow a receiving end to generatevarious kinds of images for subsequent processing using the same touchsensitive panel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating a transmitter in accordancewith an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a transmitting method in accordancewith an embodiment of the present invention.

FIG. 3 is a schematic diagram depicting a touch sensitive system inaccordance with an embodiment of the present invention.

FIG. 4 is a block diagram depicting a portion of the touch processingdevice in accordance with an embodiment of the present invention.

FIG. 5 is a block diagram depicting a portion of an analog demodulatorin accordance with an embodiment of the present invention.

FIG. 6 is a block diagram depicting a portion of a digital demodulatorin accordance with an embodiment of the present invention.

FIG. 7 is a block diagram depicting a portion of a digital demodulatorin accordance with an embodiment of the present invention.

FIG. 8 is a schematic diagram depicting the result of demodulationaccording to the digital demodulator of FIG. 7.

FIG. 9A is a flowchart illustrating a method for sensing a transmitterin accordance with an embodiment of the present invention.

FIG. 9B is a flowchart illustrating a method for sensing a transmitterin accordance with an embodiment of the present invention.

FIG. 10 is a block diagram illustrating a touch processing device inaccordance with an embodiment of the present invention.

FIG. 11 is a flowchart illustrating a touch processing method inaccordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is described in details with reference to someembodiments below. However, in addition to the disclosed embodiments,the scope of the present invention is not limited by these embodiments,rather by the scope of the claims. Moreover, in order for one withordinary skills in the art to have a better understanding and clarity ofthe descriptions, some components in the drawings may not necessary bedrawn to scale, in which some may be exaggerated relative to others, andirrelevant parts are omitted.

In an embodiment, the transmitter mentioned in the present invention maybe a stylus. In some embodiments, the transmitter may be other types ofobjects that can be placed on a touch sensitive panel or screen. Forexample, when the touch sensitive screen displays a chessboard, thetransmitter may be the chess. Once the game program detects the locationof the chess on the touch sensitive screen, it will know the location ofthe chess.

Regardless of how much contact area there is between the transmitter andthe touch sensitive panel and how many touch points there are, thetransmitter at least includes a transmitting anchor point. The touchsensitive panel or screen may detect the location of the transmittinganchor point as the representative location of an object represented bythe transmitter on the touch sensitive panel or screen. In anembodiment, the transmitter does not need to come into contact with thetouch sensitive panel, only the transmitting anchor point needs to be inproximity to the touch sensitive panel for the touch sensitive panel todetect the transmitting anchor point.

In an embodiment, the transmitter may include a plurality oftransmitting anchor points. When the touch sensitive panel detects aplurality of transmitting anchor points, it is able to detect the facingdirection of the transmitter. In another embodiment, the transmitter mayinclude m transmitting anchor points, and when the touch sensitive paneldetects n of the transmitting anchor points, it is able to detect thestance of the transmitter on the touch sensitive panel. For example, thetransmitter is a triangular body with four transmitting anchor points;each transmitting anchor point is positioned at one vertex of thetriangular body, by detecting three transmitting anchor points on thetouch sensitive panel, the touch sensitive panel will be able to knowwhich face of the triangular body is in contact with it. The transmittermay also be a square body with eight transmitting anchor points, whereeach transmitting anchor point is positioned at a vertex of the squarebody. This type of transmitter can be used as a dice.

Referring to FIG. 1, a schematic diagram illustrating a transmitter 100in accordance with an embodiment of the present invention is shown. Thetransmitter 100 includes a power supply module 110, a processing module120, a sensor module 130, a frequency synthesizer module 140, a signalamplifying module 150 and a transmitting module 160. As mentioned above,the transmitter 100 may assume the shape of a stylus. In an embodiment,the above modules may be arranged inside the stylus according to theorder shown in FIG. 1, the bottom of the stylus is to be in contact withor proximity to a touch sensitive panel. The transmitter 100 may includea master switch for turning on/off the power of the transmitter 100.

The power supply module 110 may include circuits associated with powersupply and control, such as a battery pack, a DC-to-DC voltageconverter, a power management unit and the like. The battery pack can berechargeable batteries or disposable batteries. When the battery packincludes rechargeable batteries, the power supply module 110 may furtherinclude a charger circuit for inputting an external power into therechargeable batteries. In an embodiment, the charger circuit can beincluded in the power management unit for protecting the rechargeablebatteries from over discharging and over charging.

The above processing module 120 is used for controlling the transmitter100, and may include a microprocessor. The above sensor module 130 mayinclude at least one sensor. The sensor may, for example, include apressure sensor at the tip of the stylus, a button, an accelerometer, aninductance meter, a knob, or the like. The status of the sensor may bein binary form. For example, the button may be in either a pressed-downstatus or a released status. The statuses of an accelerometer mayinclude stationary and in motion. The statuses of the sensor may includen-ary discrete values. For example, the pressure experienced by thepressure sensor may be divided into four levels, ten levels, or sixteenlevels. The statuses of the knob may also be in four levels, ten levels,or sixteen levels. The status of the sensor can also be an analoginterval. The above processing module 120 is able to detect the statusof the sensor in the sensor module 130, and generate a transmitterstatus accordingly.

The above frequency synthesizer module 140 includes a plurality offrequency generators and a frequency synthesizer or mixer. In oneembodiment, the above plurality of frequency generators may include aplurality of quartz oscillators. In another embodiment, the abovefrequency generators can use a single frequency source, and generate aplurality of frequencies through the use of dividers, frequencymultipliers, phase lock circuits and other appropriate circuitries.These frequencies are not mutually resonant frequency waves, anddifferent from and not mutually resonant with the frequency emitted bythe touch sensitive panel for detecting the transmitter 100. This avoidsinterference between the various frequencies.

In some embodiments, the ranges of the plurality of frequencies fallwithin the detectable frequency range of the touch sensitive panel. Forexample, a frequency range that generally can be detected by a touchsensitive panel is approximately between 90 kHz and 250 kHz, so thefrequencies generated by the plurality of frequency generators may fallwithin this range.

In an embodiment, the above processing module 120 may decide whichfrequencies in the plurality of frequencies are to be synthesized by thefrequency synthesizer module 140. In other words, a specific frequencycan be controlled not to be added to the mixer. Of course, the signalstrength of an individual frequency may also be controlled. In anotherembodiment, the above processing module 120 may decide the ratios of thesignal strengths of the various frequencies for the frequencysynthesizer module 140. For example, the ratio of the signal strength ofa first frequency to that of a second frequency may be 3:7. As anotherexample, the ratio of the signal strengths between a first, a second anda third frequency may be 24:47:29. One with ordinary skills in the artcan appreciate that although the frequency synthesizer module 140 can beused for generating and mixing multiple frequencies, the processingmodule 120 may also instruct the frequency synthesizer module 140 togenerate a single frequency without mixing with any other frequenciesbased on the statuses of the sensors in the sensor module 130.

In an embodiment, the signal strength of a particular frequency maycorrespond to a pressure sensor at the tip of the stylus or a knob withmultiple levels in the sensor module 130. For example, in a graphicssoftware, the pressure sensor at the tip of a stylus may indicate theshades of the color, and the degree of rotation of the knob may indicatethe diameter of the brush. Thus, the signal strength of a firstfrequency can be used to indicate the pressure on the pressure sensor,and the signal strength of a second frequency can be used to indicatethe degree of rotation of the knob.

In another embodiment, the proportion of the signal strength of onefrequency among the signal strength of the mixed frequencies can be usedto correspond to one of the n-ary statuses of a sensor. For example,when the ratio of the signal strengths of a first frequency to a secondfrequency is 3:7, it indicates the status of the sensor is in the thirdlevel among ten levels. If the ratio of the strengths is changed to 6:4,this indicates the status of the sensor is in the sixth level among tenlevels. In other words, if there are three frequencies, then the ratioof the signal strengths of a first frequency to a second frequency, theratio of the signal strengths of the second frequency to a thirdfrequency, and the ratio of the signal strengths of the third frequencyto the first frequency can be used to indicate three statuses of then-ary sensor, respectively.

The above signal amplifying module 150 is used for amplifying the signalmixed by the frequency synthesizer module 140. In an embodiment, theabove signal amplification corresponds to the pressure sensor in thesensor module 130 at the tip of the stylus. If the circuit of thepressure sensor corresponds to a variable gain amplifier (VGA) of thesignal amplifying module 150, the circuit of the pressure sensor maydirectly control the gain of the VGA without going through theprocessing module 120. Therefore, the mixed signal outputted by thefrequency synthesizer module 140 can be amplified by the VGA and sent tothe transmitting module 160.

As mentioned before, the signal strength of a particular frequency inthe mixed signal can be used to indicate a status of an n-ary sensor.The ratio of the signal strengths of two frequencies in the mixed canalso be used to indicate a status of another n-ary sensor. Meanwhile,the signal amplifying module 150 can be use to amplify the mixed signalto indicate the status of yet another n-ary sensor. For example, thetransmitter 100 includes two n-ary sensors: one is a pressure sensorprovided at the tip of the stylus, and the second one is a knob providedon the body of the stylus, they are used to indicate the color shade andthe diameter of the stylus, respectively. In an embodiment, the strengthof the mixed signal can be used to indicate the degree of pressureexperienced by the pressure sensor. The status of the knob can beindicated by the ratio of the signal strengths of two frequencies in themixed signal.

In an embodiment of the present invention, the transmitting module 160includes a pressure sensor provided at the tip of the stylus. Thetransmitting module 160 can be an array of antennas or a conductor or anelectrode with the appropriate impedance value, which can also be calledan excitation electrode. The conductor or electrode at the tip of thestylus is connected to the pressure sensor. When the transmitting module160 emits a signal and touches the touch sensitive panel/screen, thesignal will flow into the sensing electrodes of the touch sensitivepanel/screen. When the transmitting module 160 is near but not incontact with the touch sensitive panel/screen, the sensing electrodes ofthe touch sensitive panel/screen may still experience the signalvariations on the transmitting module 160, thereby allowing the touchsensitive/panel to detect the approaching of the transmitter 100.

When the frequency synthesizer module 140 synthesizes n frequencies, thefrequencies of the signal can be used to modulate 2^(n) statues. Forexample, when n equals to three, the frequencies of the signal can beused to modulate eight statues. Referring to Table 1, the transmitterstatuses and their corresponding statuses of the sensors are shown.

TABLE 1 Pressure First Second Sensor Button Button First TransmitterContact Released Released Status Pressure Second Transmitter ContactPressed Released Status Pressure Third Transmitter Contact PressedPressed Status Pressure Fourth Transmitter Contact Released PressedStatus Pressure Fifth Transmitter No Contact Released Released StatusPressure Sixth Transmitter No Contact Pressed Released Status PressureSeventh Transmitter No Contact Pressed Pressed Status Pressure EighthTransmitter No Contact Released Pressed Status Pressure

In the embodiment shown by Table 1, the sensor module 130 includes threesensors: a pressure sensor at the tip of the stylus, a first button anda second button. The status of these three sensors are all in binaryforms, so there are eight different combinations of transmitter statusesin total, as shown in Table 1. One with ordinary skills in the art canappreciate that the correspondence between the transmitter statuses andthe sensors' statuses can be arbitrarily changed. For example, the firsttransmitter status can swap with another transmitter status, forexample, the seventh transmitter status.

Referring to Table 2, the transmitter statuses and their correspondingfrequency mixings are shown. As described before, the frequencysynthesizer module 140 may synthesize three different frequencies, soeach transmitter status may correspond to a different combination of thefrequencies as shown in Table 2. One with ordinary skills in the art canappreciate that the correspondence between the transmitter statuses andthe combinations of frequencies can be arbitrarily changed. For example,the first transmitter status can swap with another transmitter status,for example, the eighth transmitter status.

TABLE 2 First Second Third Frequency Frequency Frequency FirstTransmitter Mixed Mixed Mixed Status Second Transmitter Mixed Mixed NotMixed Status Third Transmitter Mixed Not Mixed Not Mixed Status FourthTransmitter Mixed Not Mixed Mixed Status Fifth Transmitter Not MixedMixed Mixed Status Sixth Transmitter Not Mixed Mixed Not Mixed StatusSeventh Transmitter Not Mixed Not Mixed Not Mixed Status EighthTransmitter Not Mixed Not Mixed Mixed Status

In an embodiment, when the pressure sensor at the tip of the stylus isnot under any pressure, the transmitter 100 still mixes the frequenciesand sends out a signal. In another embodiment, when the pressure sensorat the tip of the stylus is not under any pressure, the transmitter 100does not mix the frequencies and transmit any signal. With respect toTable 2, this status is the seventh transmitter status. In thisembodiment, Table 1 can be altered into Table 3.

TABLE 3 Pressure First Second Sensor Button Button First TransmitterContact Released Released Status Pressure Second Transmitter ContactPressed Released Status Pressure Third Transmitter Contact PressedPressed Status Pressure Fourth Transmitter Contact Released PressedStatus Pressure Seventh Transmitter No Contact Released Released StatusPressure Seventh Transmitter No Contact Pressed Released Status PressureSeventh Transmitter No Contact Pressed Pressed Status Pressure SeventhTransmitter No Contact Released Pressed Status Pressure

In the embodiments shown in Table 1 to Table 3, the transmitter 100 usesthe synthesizing of the frequencies as the only factor of signalmodulation. In the following embodiments, in addition to frequencysynthesizing, signal strength and/or ratio of signal strengths ofdifferent frequencies are included as the factors of signal modulation.

Referring to Table. 4, transmitter frequency statuses and theircorresponding sensors' statuses in accordance with an embodiment of thepresent invention are shown. Compared to the embodiment shown in Table1, the statues sensed by the pressure sensor are not limited to twostatuses (i.e. contact pressure/no contact pressure), but more than twostatuses. Thus, the left column of Table 4 is not called transmitterstatus anymore, but rather transmitter frequency status. The modulationfactors of the transmitter status of this embodiment include, inaddition to the frequency status, the signal strength as well.

TABLE 4 First Second Pressure Sensor Button Button First TransmitterContact Pressure Released Released Frequency Status Level > 0 SecondTransmitter Contact Pressure Pressed Released Frequency Status Level > 0Third Transmitter Contact Pressure Pressed Pressed Frequency StatusLevel > 0 Fourth Transmitter Contact Pressure Released Pressed FrequencyStatus Level > 0 Fifth Transmitter Contact Pressure Released ReleasedFrequency Status Level = 0 Sixth Transmitter Contact Pressure PressedReleased Frequency Status Level = 0 Seventh Transmitter Contact PressurePressed Pressed Frequency Status Level = 0 Eighth Transmitter ContactPressure Released Pressed Frequency Status Level = 0

Referring to Table 5, transmitter statuses and their correspondingfrequency mixings and signal strengths in accordance with an embodimentof the present invention are shown. The signal strength modulation canbe the signal strength value of the mixed signal to indicate, forexample, the contact pressure level of the pressure sensor.

TABLE 5 First Second Third Frequency Frequency Frequency FirstTransmitter Mixed Mixed Mixed Frequency Status + Signal StrengthModulation Second Transmitter Mixed Mixed Not Mixed Frequency Status +Signal Strength Modulation Third Transmitter Mixed Not Mixed Not MixedFrequency Status + Signal Strength Modulation Fourth Transmitter MixedNot Mixed Mixed Frequency Status + Signal Strength Modulation FifthTransmitter Not Mixed Mixed Mixed Frequency Status + Signal StrengthModulation Sixth Transmitter Not Mixed Mixed Not Mixed FrequencyStatus + Signal Strength Modulation Seventh Transmitter Not Mixed NotMixed Not Mixed Frequency Status + Signal Strength Modulation EighthTransmitter Not Mixed Not Mixed Mixed Frequency Status + Signal StrengthModulation

In the embodiment of Table 5, the contact pressure levels of thepressure sensor corresponding to the fifth to the eighth transmitterfrequency statues are all zero, so the results of signal strengthmodulation can also be zero. In other words, no signal is transmitted.In another embodiment, such a signal strength modulation can be aconstant. This constant signal strength can be different from the signalstrengths corresponding to other contact pressure levels of the pressuresensor.

Referring to FIG. 2, a flowchart illustrating a transmitting method inaccordance with an embodiment of the present invention is shown. Thetransmitting method is applicable to the transmitter 100 shown in FIG.1, but not limited thereto. The transmitting method includes two steps.In step 210, a transmitter status is generated based on a status insidea sensor module included in the transmitter. In step 220, an electricalsignal is transmitted to a touch sensitive device according to thetransmitter status, so that after analyzing the electrical signal, thetouch sensitive device is able to find out the transmitter status and arelative position of the transmitter with respect to the touch sensitivedevice. The electrical signal is mixed from a plurality of signalshaving different frequencies.

In an embodiment, a sensor inside the sensor module includes one of thefollowing: a button, a knob, a pressure sensor (or a pressure gauge), anaccelerometer or a gyroscope. The pressure sensor can be used to sensethe contact pressure level between the transmitter and the touchsensitive device.

When the sensor module includes a plurality of sensors, the number ofpossible statues of the transmitter status is the sum of the number ofpossible statues of every sensor. Alternatively, in another embodiment,the transmitter status indication is one of arbitrary combinations ofevery sensor's status indication. In an embodiment, the statusindication of a sensor inside the sensor module is the nth power of two,wherein n is an integer greater than or equal to 0.

The modulation factor of the electrical signal includes one or acombination of: frequency and strength. In an embodiment, the totalsignal strength of the electrical signal corresponds to a status of ann-ary sensor in the sensor module. In another embodiment, the ratio ofsignal strengths of a first frequency to a second frequency mixed in theelectrical signal corresponds to a status of an n-ary sensor in thesensor module. In yet another embodiment, the total signal strength ofthe electrical signal corresponds to a status of a first n-ary sensor inthe sensor module, wherein the ratio of the signal strengths of a firstfrequency to a second frequency mixed in the electrical signalcorresponds to a status of a second n-ary sensor in the sensor module.

One main principle of the present invention lies in the use of anelectrical signal mixed from a plurality of frequencies, so that a touchsensitive device may be able to detect the position of a transmittertransmitting the electrical signal and the status of at least one sensoron the transmitter.

Referring now to FIG. 3, a schematic diagram depicting a touch sensitivesystem 300 in accordance with an embodiment of the present invention isshown. The touch sensitive system 300 includes at least one transmitter100, a touch sensitive panel 320, a touch processing device 330 and amainframe 340. In this embodiment, the transmitter 100 is applicable tothe transmitters described in the previous embodiments, especially theembodiments shown in FIGS. 1 and 2. It should also be noted that thetouch sensitive system 300 may include a plurality of transmitters 100.The touch sensitive panel 320 is formed on a substrate. The touchsensitive panel 320 can be a touch sensitive screen, but the presentinvention does not restrict the form of the touch sensitive panel 320.

In an embodiment, a touch sensitive area of the touch sensitive panel320 includes a plurality of first electrodes 321 and a plurality ofsecond electrodes 322. A plurality of sensing points are formed at theintersections of these two electrodes. These first electrodes 321 andsecond electrodes 322 are connected to the touch processing device 330.Under mutual capacitive sensing, the first electrodes 321 can be calledfirst conductive strips or driving electrodes and the second electrodes322 can be called second conductive strips or sensing electrodes. Thetouch processing device 330 is able to know the approach or touch(approach/touch) of any external conductive object on the touchsensitive panel 320 by first providing a driving voltage to the firstelectrodes 321 and then measuring the signal variations of the secondelectrodes 322. One with ordinary skills in the art can appreciate thatthe touch processing device 330 may use mutual- or self-capacitivesensing methods to detect an approaching/touching event or object, andthey will not be further described. In addition to mutual- orself-capacitive sensing methods, the touch processing device 330 mayalso detect the electrical signal emitted by the transmitter 100 inorder to detect the relative position of the transmitter 100 withrespect to the touch sensitive panel 320. The detection principle willbe detailed in the later sections of the specification.

FIG. 3 further includes a mainframe 340, which can be an operatingsystem such as a CPU or a main processor in an embedded system, or othertypes of computers. In an embodiment, the touch sensitive system 300 canbe a table PC. The mainframe 340 can be a CPU for executing theoperating programs of the table PC. For example, the table PC executesan Android operating system, and the mainframe 340 is an ARM processorexecuting the Android operating system. The present invention does notlimit the form of information transmission between the mainframe 340 andthe touch processing device 330 as long as the information transmittedis relevant to the approaching/touching event(s) happened on the touchsensitive panel 320.

Referring to FIG. 4, a block diagram depicting a portion of the touchprocessing device 330 in accordance with an embodiment of the presentinvention is shown. As mentioned earlier, the touch processing device330 may use mutual- or self-capacitive sensing principle to detect anapproaching/touching event, so details related to capacitive sensingwill not be described hereinafter. The embodiment shown in FIG. 4includes a receiver analog front end 410 and a demodulator 420.

The receiver analog front end 410 is connected to the first electrodes321 or the second electrodes 322 described before. In an embodiment,each of the first electrodes 321 and each of the second electrodes 322are connected to a receiver analog front end 410, respectively. Inanother embodiment, a plurality of first electrodes 321 form a set, anda plurality of second electrodes 322 form a set, and each set of firstelectrodes 321 corresponds to a receiver analog front end 410, and eachset of second electrodes 322 corresponds to another receiver analogfront end 410. Each receiver analog front end 410 receives in turn thesignal of the first electrodes 321 or second electrodes 322 in the set.In another embodiment, a set of first electrodes 321 and a set of secondelectrodes 322 correspond to one receiver analog front end 410. Thereceiver analog front end 410 can first be connected in turn to thefirst electrodes 321 in the set of the first electrodes 321, and thenconnected in turn to the second electrodes 322 in the set of the secondelectrodes 322. On the contrary, the receiver analog front end 410 canfirst be connected in turn to the second electrodes 322 in the set ofthe second electrodes 322, and then connected in turn to the firstelectrodes 321 in the set of the first electrodes 321. In an embodiment,the touch processing device 330 may include only one receiver analogfront end 410. One with ordinary skills in the art can appreciate thatthe present invention does not limit how the first electrodes 321 or thesecond electrodes 322 are configured to the receiver analog front end410. In other words, the number of receiver analog front ends 410included in the touch processing device 330 may be smaller than or equalto the sum of the first electrodes 321 and the second electrodes 322.

The receiver analog front end 410 may perform some filtering, amplifyingor other types of analog signal processing. In some embodiments, thereceiver analog front end 410 can receive the difference between twoadjacent first electrodes 321, or the difference between two adjacentsecond electrodes 322. In an embodiment, each receiver analog front end410 can output to a demodulator 420. In another embodiment, every n^(th)receiver analog front end 410 may output to a demodulator 420. In yetanother embodiment, each receiver analog front end 410 may output to Ndemodulators 420, wherein N is a positive integer greater than or equalto one. In some embodiments, the touch processing device 330 may includeonly one demodulator 420. One with ordinary skills in the art canappreciate that the present invention does not limit how the receiveranalog front end(s) 410 is/are configured to the demodulator(s) 420.

The demodulator 420 is used to demodulate the electrical signaltransmitted by the transmitter 100 in order to obtain information oneach frequency and information on the signal strengths in the receivedsignals of the corresponding first electrodes 321 or second electrodes322. For example, the transmitter 100 may transmit a signal having threefrequencies. The demodulator 420 may obtain the signal strengths forthese three frequencies, the ratio(s) of signal strengths of each two orarbitrary two frequencies, and the overall signal strength. In thepresent invention, the demodulator 420 can be implemented in a digitalor analog way; it is described in the following three embodiments.

Referring to FIG. 5, a block diagram depicting a portion of an analogdemodulator 420 in accordance with an embodiment of the presentinvention is shown. A single analog demodulator shown in FIG. 5 can beused to demodulate every frequency, or a plurality of analogdemodulators shown in FIG. 5 can be used to demodulate a plurality offrequencies. For example, when the transmitter 100 transmits Nfrequencies, N of the analog demodulator shown in FIG. 5 are used todemodulate each of the frequencies. A signal generator 510 is used togenerate signals of corresponding frequencies.

An analog signal received from the receiver analog front end 410 can bepassed through an optional amplifier (not shown) and then to two mixers520I and 520Q. The mixer 520I receives a cosine signal outputted by thesignal generator 510, while the mixer 520Q receives a sine signaloutputted by the signal generator 510. The mixer signals outputted bythe mixers 520I and 520Q are then sent to integrators 530I and 530Q,respectively. Then, the integrated signals are sent to squarers 540I and540Q by the integrators 530I and 530Q, respectively. Finally, theoutputs of the squarers 540I and 540Q are summed and thenroot-mean-squared by a “Root Mean Square (RMS) of Sum” element. As such,the signal strengths corresponding to the signal frequencies generatedby the signal generator 510 can be obtained. After the signal strengthsof all frequencies are obtained, the ratio(s) of the signal strengths ofeach two or arbitrary two frequencies and the overall signal strengthcan then be generated.

Referring to FIG. 6, a block diagram depicting a portion of a digitaldemodulator 420 in accordance with an embodiment of the presentinvention is shown. Compared to the embodiment shown in FIG. 5, theembodiment shown in FIG. 6 is carried out in a digital manner.Similarly, a single digital demodulator shown in FIG. 6 can be used todemodulate every frequency, or a plurality of the digital demodulatorsshown in FIG. 6 can be used to demodulate a plurality of frequencies.For example, when the transmitter 100 transmits N frequencies, N of thedigital demodulator shown in FIG. 6 are used demodulate each of thefrequencies. A signal generator 610 is used to generate digital signalsof corresponding frequencies.

An analog signal received from the receiver analog front end 410 can bepassed through an optional amplifier 600 and then to ananalog-to-digital converter (ADC) 605. The sampling frequency of the ADC605 will correspond to the frequency of the signal transmitted by thesignal generator 610. In other words, when the ADC 605 is performing onesampling, the signal generator 610 will send out signals to two mixers620I and 620Q once. The mixer 620I receives a cosine signal outputted bythe signal generator 610, while the mixer 620Q receives a sine signaloutputted by the signal generator 610. The mixer signals outputted bythe mixers 620I and 620Q are then outputted to addition integrators 630Iand 630Q, respectively. Then, the addition-integrated signals are sentto squarers 640I and 640Q by the addition integrators 630I and 630Q,respectively. Finally, the outputs of the squarers 640I and 640Q aresummed and root-mean-squared by a “Root Mean Square (RMS) of Sum”element. As such, the signal strengths corresponding to the signalfrequencies generated by the signal generator 610 can be obtained. Afterthe signal strengths of all frequencies are obtained, the ratios of thesignal strengths of each two frequencies and the overall signal strengthcan then be generated.

Referring to FIG. 7, a block diagram depicting a portion of a digitaldemodulator 420 in accordance with an embodiment of the presentinvention is shown. The embodiment shown in FIG. 7 is carried out in adigital manner, and a single digital demodulator shown in FIG. 7 can beused to demodulate every frequency. An analog signal received from thereceiver analog front end 410 can be passed through an optionalamplifier 700 and then to an analog-to-digital converter (ADC) 705.Then, the outputted digital signal is sent to a Fourier transformer 720to demodulate the signal strength of each frequency on the frequencydomain. The above Fourier transformer can be a digitalized Fast Fouriertransformer.

Referring to FIG. 8, a schematic diagram depicting the result ofdemodulation according to the digital demodulator 420 of FIG. 7 isshown. The result shown in FIG. 8 is merely an illustration, in additionto being represented by a diagram; other kinds of data structure can beused to store the result of demodulation. The horizontal axis shown inFIG. 8 indicates the signal frequency, and the vertical axis thereofindicates the signal strength. The calculated result from the Fouriertransformer 720 gives the signal strengths corresponding to Nfrequencies possibly transmitted by the transmitter 100. In anembodiment, a threshold can be set for the signal strength. Only asignal with strength greater than the threshold would be regarded as asignal having a corresponding frequency. When the signal strength ofeach frequency is obtained, the ratios of each two frequencies and theoverall signal strength can then be calculated.

Although the embodiments of the three demodulators 420 provided in FIGS.5 to 7 can be implemented in the touch processing device 330 shown inFIG. 3, but the present invention does not restrict that the touchprocessing device 330 must implement all the steps of the demodulator420. In some embodiments, some steps of the demodulator 420 can beperformed by the mainframe 340. It should be noted that although theembodiments of the demodulators 420 can be implemented by specifichardware, but one with ordinary skills in the art can appreciate thateach elements of the demodulators 420 can be implemented throughsoftware or firmware. For example, the mixers can be implemented bymultiplication, and the addition integrators can be implemented byaddition. Multiplication and addition are among the most commonoperation instructions in ordinary processors.

Referring to FIG. 9A, a flowchart illustrating a method for sensing atransmitter in accordance with an embodiment of the present invention isshown. In step S910, the overall signal strength of the electricalsignal received by every one of the first and second electrodes iscalculated. Step 910 can be implemented using the embodiments shown inFIGS. 3 to 7. Then, in step 920, based on the calculated overall signalstrength, a relative position of the transmitter with respect to a touchsensitive device is calculated. In an embodiment, the position of thetransmitter is thought to be corresponding to the first and secondelectrodes having the largest overall signal strengths. In anotherembodiment, the position of the transmitter is thought to becorresponding to the centroid of adjacent first and second electrodeshaving the largest overall signal strengths, the magnitude of the massesof these electrodes correspond to the strength of the signals. Finally,in an optional step 930, based on information of the electrical signaltransmitted by the transmitter, a transmitter status is calculated. Onewith ordinary skills in the art can appreciate that the implementationof step 930 can be deduced from the tables previously described.

Referring to FIG. 9B, a flowchart illustrating a method for sensing atransmitter in accordance with an embodiment of the present invention isshown. In step 905, the overall signal strength of the electrical signalreceived by every first or second electrode is calculated. Once theelectrical signal received by a first or second electrode isdemodulated, the frequencies of the signal transmitted by thetransmitter can be known. For example, if the transmitter transmits afirst frequency and a second frequency, but not a third frequency, thenin the calculation of overall signal strengths of another electrodecarried out in step 915, the calculation of the third frequency can beomitted. If the digital demodulator shown in FIG. 7 is employed, thenthe method shown in FIG. 9B is not required. However, if the demodulatordescribed with respect to FIG. 5 or FIG. 6 is employed, and that thenumber of demodulators is not be enough to scan all frequencies in onego, then the method of FIG. 9B can save some time and calculationresources. Moreover, if after the calculations of the first electrodesor the second electrodes, no electrical signal transmitted by thetransmitter is found, step 915 can be bypassed. On the contrary, if theelectrical signal transmitted by the transmitter is found, then step 915can calculate the overall signal strength of the electrical signalreceived by another electrode based on the signal strength of eachfrequency of the received electrical signal. The descriptions of theembodiment of FIG. 9A apply to the remaining steps 920 and 930.

It should be noted that in the processes of FIGS. 9A and 9B, if nocause-and-effect relationships or order between the steps are mentioned,then the present invention does not limit the order in which these stepsare carried out. In addition, in steps 905, 910 and 915, the overallsignal strength of the electrical signal of every first and/or secondelectrode(s) is mentioned. In an embodiment, if the touch sensitivesystem 300 includes only a single transmitter 100, the processes ofFIGS. 9A and 9B will be modified to: if the overall strength of theelectrical signal received by at least one first electrode and secondelectrode is calculated to be greater than a threshold, then executesteps 920 and 930.

In an embodiment, the present invention provides a method for detectinga transmitter approximating or touching a touch sensitive device. Thetransmitter transmits an electrical signal mixed by signals having aplurality of frequencies. The touch sensitive device includes aplurality of first electrodes, a plurality of second electrodes and aplurality of sensing points intersected by those first and secondelectrodes. The method includes the following steps of: calculating thetotal signal strength of the electrical signal received by each of thefirst electrodes and second electrodes; and calculating a relativeposition between the transmitter and the touch sensitive deviceaccording to the calculated total signal strengths.

The above step of calculating the total signal strength of theelectrical signal received by each of the first electrodes and secondelectrodes further includes: calculating the strength of a signalcorresponding to each of the plurality of frequencies in the receivedelectrical signal; and summing all of the calculated strengths ofsignals corresponding to the plurality of frequencies. In an embodiment,the above step of calculating the strength of a signal corresponding toa particular frequency of the plurality of frequencies further includes:mixing an in-phase signal with the received signal to generate anin-phase analog signal, mixing an orthogonal signal with the receivedsignal to generate an orthogonal analog signal, wherein the frequency ofthe in-phase signal and the orthogonal signal is the particularfrequency; performing integration on the in-phase analog signal togenerate an in-phase integration signal, performing integration on theorthogonal analog signal to generate an orthogonal integration signal;and calculating the root mean square of the sum of the square of thein-phase integration signal and the square of the orthogonal integrationsignal to obtain the signal strength corresponding to the particularfrequency. In another embodiment, the above step of calculating thestrength of a signal corresponding to a particular frequency of theplurality of frequencies further includes: performing analog-to-digitalconversion on the received signal to produce a digital received signal;mixing an in-phase signal with the digital received signal to generatean in-phase digital signal; mixing an orthogonal signal with thereceived signal to generate an orthogonal digital signal, wherein thefrequency of the in-phase signal and the orthogonal signal is theparticular frequency; performing addition integration on the in-phasedigital signal to generate an in-phase integration signal; performingaddition integration on the orthogonal digital signal to generate anorthogonal integration signal; and calculating the root mean square ofthe sum of the square of the in-phase integration signal and the squareof the orthogonal integration signal to obtain the strength of signalcorresponding to the particular frequency. The frequency of theanalog-to-digital conversion corresponds to the particular frequency. Instill another embodiment, the above step of calculating the strength ofa signal corresponding to a particular frequency of the plurality offrequencies further includes: performing analog-to-digital conversion onthe received signal to produce a digital received signal; and performingFourier transform on the digital received signal to generate thestrength of the signal corresponding to each frequency of the pluralityof frequencies.

The above step of calculating the total signal strength of theelectrical signal received by each of the first electrodes and secondelectrodes further includes: calculating the total signal strength ofthe electrical signal received by each first electrode; calculating thestrength of a signal corresponding to each of the plurality offrequencies based on the electrical signal received by at least onefirst electrode to obtain a set of frequencies mixed by the transmitter;and calculating the total signal strength corresponding to all of thefrequencies in the set of frequencies in the electrical signal receivedby the second electrode, wherein a signal strength corresponding to eachfrequency in the set of frequencies is greater than a threshold.

In an embodiment, while calculating the total signal strength of theelectrical signal received by a particular first electrode, the totalsignal strength of the electrical signal received by a particular secondelectrode is calculated.

The transmitter transmits the electrical signal according to atransmitter status. The method further includes calculating thetransmitter status based on the information of the electrical signal.The above calculating the transmitter status is based on one or anyarbitrary combination of the following information of the electricalsignal: the signal strength of a particular frequency in the pluralityof frequencies mixed by the electrical signal; the total signal strengthof the electrical signal; and the ratio of signal strengths of a firstfrequency to a second frequency in the plurality of frequencies mixed bythe electrical signal. In an embodiment, the total signal strength ofthe electrical signal corresponds to the status of a sensor with n-arypossible statuses in the transmitter. In another embodiment, the ratioof the signal strengths of the first frequency to the second frequencymixed by the electrical signal corresponds to the status of a sensorwith n-ary possible statuses in the transmitter. In still anotherembodiment, the total signal strength of the electrical signalcorresponds to the status of a first sensor with n-ary possible statusesin the transmitter, wherein the ratio of signal strengths of the firstfrequency to the second frequency in the plurality of frequencies mixedby the electrical signal corresponds to the status of a second sensorwith n-ary possible statuses in the transmitter.

In an embodiment, when the transmitter includes a plurality of sensors,the number of possible statuses of the transmitter status is the sum ofthe number of possible statuses of every one of the plurality ofsensors. In another embodiment, the transmitter status indication is oneof arbitrary combinations of every sensor's status indication.

The present invention provides a touch processing device for detecting atransmitter approximating or touching a touch sensitive device. Thetransmitter transmits an electrical signal mixed by signals having aplurality of frequencies. The touch sensitive device includes aplurality of first electrodes, a plurality of second electrodes and aplurality of sensing points intersected by those first and secondelectrodes. The touch processing device is used for: calculating thetotal signal strength of the electrical signal received by each of thefirst electrodes and second electrodes; and calculating a relativeposition between the transmitter and the touch sensitive deviceaccording to the calculated total signal strengths.

The above step of calculating the total signal strength of theelectrical signal received by each of the first electrodes and secondelectrodes further includes: calculating the strength of a signalcorresponding to each of the plurality of frequencies in the receivedelectrical signal; and summing all of the calculated strengths ofsignals corresponding to the plurality of frequencies. In an embodiment,the touch processing device further includes a demodulator forcalculating the strength of a signal corresponding to a particularfrequency of the plurality of frequencies. The demodulator furtherincludes: a signal generator for generating an in-phase signal and anorthogonal signal, wherein the frequency of the in-phase signal and theorthogonal signal is the particular frequency; at least a mixer formixing the in-phase signal with the received signal to generate anin-phase analog signal, and mixing the orthogonal signal with thereceived signal to generate an orthogonal analog signal; at least anintegrator for performing integration on the in-phase analog signal togenerate an in-phase integration signal, and performing integration onthe orthogonal analog signal to generate an orthogonal integrationsignal; at least a squarer for calculating the square of the in-phaseintegration signal and the square of the orthogonal integration signal;and at least a “Root Mean Square (RMS) of Sum” element for calculatingthe root mean square of the sum of the square of the in-phaseintegration signal and the square of the orthogonal integration signalto obtain the signal strength corresponding to the particular frequency.In another embodiment, the touch processing device further includes ademodulator for calculating the strength of a signal corresponding to aparticular frequency of the plurality of frequencies. The demodulatorfurther includes: an analog-to-digital converter (ADC) for performinganalog-to-digital conversion on the received signal to produce a digitalreceived signal; a signal generator for generating an in-phase signaland an orthogonal signal, wherein the frequency of the in-phase signaland the orthogonal signal is the particular frequency; at least a mixerfor mixing the in-phase signal with the digital received signal togenerate an in-phase digital signal, and mixing the orthogonal signalwith the digital received signal to generate an orthogonal digitalsignal; at least an addition integrator for performing additionintegration on the in-phase digital signal to generate an in-phaseintegration signal, and performing integration on the orthogonal digitalsignal to generate an orthogonal integration signal; at least a squarerfor calculating the square of the in-phase integration signal and thesquare of the orthogonal integration signal; and at least a “Root MeanSquare (RMS) of Sum” element for calculating the root mean square of thesum of the square of the in-phase integration signal and the square ofthe orthogonal integration signal to obtain the signal strengthcorresponding to the particular frequency. In still another embodiment,the touch processing device further includes a demodulator forcalculating the strength of a signal corresponding to each of theplurality of frequencies. The demodulator further includes: ananalog-to-digital converter (ADC) for performing analog-to-digitalconversion on the received signal to produce a digital received signal;and a Fourier Transformer for performing Fourier Transform on thedigital received signal to generate the strength of the signalcorresponding to each of the plurality of frequencies.

In an embodiment, the step of calculating the total signal strength ofthe electrical signal received by each of the first electrodes andsecond electrodes further includes: calculating the total signalstrength of the electrical signal received by each first electrode;calculating the strength of a signal corresponding to each of theplurality of frequencies based on the electrical signal received by atleast one first electrode to obtain a set of frequencies mixed by thetransmitter; and calculating the total signal strength corresponding toall of the frequencies in the set of frequencies in the electricalsignal received by the second electrode, wherein a signal strengthcorresponding to each frequency in the set of frequencies is greaterthan a threshold.

While calculating the total signal strength of the electrical signalreceived by a particular first electrode, the total signal strength ofthe electrical signal received by a particular second electrode iscalculated.

The transmitter transmits the electrical signal according to atransmitter status. The touch processing device further includescalculating the transmitter status based on the information of theelectrical signal. The above calculating the transmitter status is basedon one or any arbitrary combination of the following information of theelectrical signal: the signal strength of a particular frequency in theplurality of frequencies mixed by the electrical signal; the totalsignal strength of the electrical signal; and the ratio of signalstrengths of a first frequency to a second frequency in the plurality offrequencies mixed by the electrical signal.

In an embodiment, the total signal strength of the electrical signalcorresponds to the status of a sensor with n-ary possible statuses inthe transmitter. In another embodiment, the ratio of the signalstrengths of the first frequency to the second frequency mixed by theelectrical signal corresponds to the status of a sensor with n-arypossible statuses in the transmitter. In still another embodiment, thetotal signal strength of the electrical signal corresponds to the statusof a first sensor with n-ary possible statuses in the transmitter,wherein the ratio of signal strengths of the first frequency to thesecond frequency in the plurality of frequencies mixed by the electricalsignal corresponds to the status of a second sensor with n-ary possiblestatuses in the transmitter.

In an embodiment, when the transmitter includes a plurality of sensors,the number of possible statuses of the transmitter status is the sum ofthe number of possible statuses of every one of the plurality ofsensors. In another embodiment, the transmitter status indication is oneof arbitrary combinations of every sensor's status indication.

The present invention provides a touch processing system for detecting atransmitter approximating or touching a touch sensitive device. Thetransmitter transmits an electrical signal mixed by signals having aplurality of frequencies. The touch processing system includes: thetouch sensitive device including a plurality of first electrodes, aplurality of second electrodes and a plurality of sensing pointsintersected by those first and second electrodes; and a touch processingdevice for calculating the total signal strength of the electricalsignal received by each of the first electrodes and second electrodes;and calculating a relative position between the transmitter and thetouch sensitive device according to the calculated total signalstrengths.

In summary, one of the main principles of the present invention lies indetecting the signal strengths corresponding to a plurality offrequencies in the signal received by the first electrodes and thesecond electrodes in order to calculate a relative position of thetransmitter with respect to the touch sensitive device, and to obtainthe statues of various sensors on the transmitter based on the derivedtransmitter status. Moreover, the present invention may also make use ofthe touch sensitive electrodes of capacitive touch sensitive panels,thus allowing the same capacitive touch sensitive panel to perform bothcapacitive sensing and the detection of the transmitter. In other words,the same capacitive touch sensitive panel can be used for the detectionsof fingers, palms, as well as transmitter-type styli.

Referring back to FIG. 3, various kinds of buses or physical connectionsmay be employed between the touch processing device 330 and themainframe 340. For example, a high-speed bus such as PCI-Express,HyperTransport, SLI or CrossFire or a low speed transmission interfacesuch as USB, I²C or SPI can be used. In addition, information can betransmitted in a “shared-memory” manner between the two. The presentinvention does not limit the type of connection between the two as longas the transmitted information is related to touch sensitiveinformation.

In an embodiment, the transmitted information may include a relativeposition of the transmitter 100 with respect to the touch sensitivepanel 320 and the transmitter status. The mainframe 340 can betransparent to how the touch processing device 330 calculates therelative position and the transmitter status. This embodiment is moreappropriate for a low-speed bus. In another embodiment, the touchprocessing device 330 may only detect and collect touch sensitivesignals, while higher-end functions are performed by the mainframe 340.As such, the cost of the touch processing device 330 can be reduced, andthe more powerful mainframe 340 with larger computational resources canbe fully utilized. Moreover, it is easier to update the software of themainframe 340, so it is more flexibility to modify, correct, update andadd touch sensitive functions.

For the mainframe 340, the touch sensitive panel 320 includes aplurality of sensing points. Each sensing point is composed of a pair ofintersecting first electrode 321 and second electrode 322. The sensinginformation of all the sensing points can be calculated to determine theposition of an approaching/touching event. Thus, the touch processingdevice 330 may provide various two-dimensional (2D) sensing informationto the mainframe 340. In an embodiment, the 2D sensing informationcorresponds to every sensing point on the touch sensitive panel 320.However, in another embodiment, the 2D sensing information correspondsto a portion of the sensing points on the touch sensitive panel 320. Thepresent invention does not limit the number of sensing points to whichthe 2D sensing information corresponds, as long as the 2D sensinginformation corresponds to two or more first electrodes 321 and secondelectrodes 322.

In an embodiment, when a plurality of the first electrodes 321 of thetouch sensitive panel 320 transmits a driving signal, the transmitter100 will transmit an electrical signal upon detecting the drivingsignal. The electrical signal can then be detected by the demodulator asmentioned before, or by a capacitive detecting module 1030. If thesignal is detected by the demodulator, then the frequencies mixed in theelectrical signal as well as the particular second electrodes 322detecting the signal can be determined. If the signal is detected by thecapacitive detecting module 1030, only the particular second electrodes322 detecting the signal can be determined.

In a mutual-capacitive detection embodiment, since the capacitivedetecting module 1030 instructs the plurality of the first electrodes321 to transmit the driving signal sequentially, if the transmitter 100does not detect the driving signal transmitted by a particular firstelectrode 321, it will not generate an electrical signal. As a result,none of the first electrodes 321 will detect any electrical signal.However, if the transmitter 100 detects the driving signal transmittedby a particular first electrode 321, it will generate an electricalsignal. Thus, a transmitter detecting module 1010 will know that thetransmitter 100 is close to that particular first electrode 321.Further, some second electrodes 322 will also detect the electricalsignal, so the transmitter detecting module 1010 and/or the capacitivedetecting module 1030 may also know that the transmitter is close tothose second electrodes 322. As such, simply using the signals receivedby the plurality of second electrodes 322, a 2D sensing information canbe obtained. Furthermore, using the signals received by all of thesecond electrodes 322 in the same period of time, the transmitterdetecting module 1010 may generate a 2D sensing information, and thecapacitive detecting module 1030 may also generate a 2D sensinginformation.

In an embodiment, a 2D sensing information may include the strength ofthe signals transmitted by the transmitter 100. In another embodiment, a2D sensing information may include the signal strength of a plurality offrequencies mixed by the transmitter. For example, the transmitter mixesthree frequencies, so a 2D sensing information includes the signalstrength of a first frequency, another 2D sensing information includesthe signal strength of a second frequency, and yet another 2D sensinginformation includes the signal strength of a third frequency. In thisembodiment, since the signal strengths of these three frequencies areknown to the mainframe 340, the signal strengths of the variousfrequencies with respect to the same sensing point can be added togetherto obtain the strength of the signal transmitted by the transmitter 100.

The 2D sensing information above does not necessarily include absolutevalues; it may also include relative values. For example, after thesignal strength of a first frequency is transmitted, the 2D sensinginformation may include the difference between the signals strengths ofthe second frequency and the first frequency, and the differencesbetween the signal strengths of the third frequency with respect to thefirst/second frequencies. Alternatively, the 2D sensing information mayinclude the ratio of the signals strengths of the second frequency tothe first frequency and the ratios of the signal strengths of the thirdfrequency to the first/second frequencies. In an embodiment, the signalstrength of the total signal can be transmitted first, and the ratios ofeach frequency with respect to the total signal are then transmitted. Itis mentioned earlier that the modulation of some information involvesthe use of ratios of the signal strengths of some frequencies, so bytransmitting the ratios, the computations performed by the mainframe 340can be omitted. Of course, the mainframe 340 may also perform restoringcalculations on the differences or ratios to restore the original signalstrengths.

In an embodiment, the touch processing device 330 may know that theelectrical signal transmitted by the transmitter 100 is a mix of firstand second frequencies during a previous detection, so the touchprocessing device 330 can transmit two 2D sensing information; the first2D sensing information corresponds to the first frequency, and thesecond 2D sensing information corresponds to the second frequency. In alatter detection, due to a change in the transmitter status in thetransmitter 100, the electrical signal transmitted by the transmitter100 is a mixture of the first frequency, the second frequency and athird frequency, the touch processing device 330 will then have totransmit three 2D sensing information, especially a third 2D sensinginformation corresponding to the third frequencies. On the other hand,during a latter detection, due to a change in the transmitter status inthe transmitter 100, the electrical signal transmitted by thetransmitter 100 includes only a single frequency; the touch processingdevice 330 will only need to transmit one 2D sensing information.Nonetheless, the present invention does not restrict the touchprocessing device 330 to transmitting only a corresponding 2D sensinginformation for any received frequency. In an embodiment, the touchprocessing device 330 may transmit a corresponding 2D sensinginformation for each of the supported frequencies, regardless of whetherthey are mixed by the transmitter 100 or not.

The above 2D sensing information may include a plurality ofone-dimensional (1D) sensing information. In an embodiment, each 1Dsensing information may include the sensing information of all thesensing points along one axial direction. In another embodiment, a 1Dsensing information may include the sensing information of a portion ofsensing points along one axial direction. For example, when the signalstrength corresponding to this partial sensing point is not a zerovalue, the 1D sensing information records the positions of the non-zerosensing points and their signal strengths. These 1D sensing informationare called Line Piece (LPC). In other words, the above 2D sensinginformation may include a plurality of line pieces. Of course, a 1Dsensing information included in the line piece may also be a zero value.For example, when the line piece may represent the difference betweenthe signal strengths of a frequency and another frequency, thedifference may be zero.

As mentioned before, when the touch processing device 330 transmitstouch sensitive information to the mainframe 340, it may include aplurality of 2D sensing information. These 2D sensing information may betransmitted in a time-division multiplexing manner. For example, thesignal strength of a first frequency with respect to a first horizontalaxis is transmitted first, then the signal strength of a secondfrequency with respect to the first horizontal axis is transmitted.After that, the signal strength of the first frequency with respect to asecond horizontal axis is transmitted first, then the signal strength ofa second frequency with respect to the second horizontal axis istransmitted, and so on until the signal strengths of the first andsecond frequencies with respect to all the horizontal axes aretransmitted. Upon receiving them, the mainframe 340 may divide them intotwo 2D sensing information; the first 2D sensing information concernsthe signal strengths of the first frequency with respect to all thesensing points, and the second 2D sensing information concerns thesignal strengths of the second frequency with respect to all the sensingpoints. In another embodiment, the touch processing device 330 maytransmit a first 2D sensing information first, and then transmit asecond 2D sensing information. The present invention does not limit themanner in which the 2D sensing information are transmitted.

In addition to detection of the transmitter 100, the touch processingdevice 330 may also perform capacitive sensing through the plurality ofthe first electrodes 321 and the second electrodes 322. For example, thefirst electrodes 321 are sequentially supplied with a driving voltage,and the changes in capacitances are measured on the second electrodes322 for mutual capacitive sensing, or the change in capacitance of eachelectrode is measured sequentially for self capacitive sensing. Whenperforming capacitive sensing, the touch processing device 330 maygenerate a 2D capacitive sensing information corresponding to themeasured capacitances. These 2D capacitive sensing information can beused for finding an external conductive object approaching or touchingthe touch sensitive panel 320.

In an embodiment, since the touch processing device 330 performstransmitter detection at a different time from capacitive sensing, sothe 2D capacitive sensing information is transmitted separately from theabovementioned plurality of 2D sensing information. However, in anotherembodiment, the touch processing device 330 can temporary store aparticular kind of 2D sensing information, and transmit the transmitterdetection information and the capacitive sensing information in atime-division multiplex manner. For example, the touch processing device330 may transmit the signal strength of a first frequency with respectto a first horizontal axis, then the signal strength of a secondfrequency with respect to the first horizontal axis, and finally thecapacitive sensing information with respect to the first horizontalaxis. Subsequently, the touch processing device 330 may transmit thesignal strength of the first frequency with respect to a secondhorizontal axis, then the signal strength of the second frequency withrespect to the second horizontal axis, and finally the capacitivesensing information with respect to the second horizontal axis, and soforth until the signal strengths of the first and second frequencies andthe capacitive sensing information with respect to all the horizontalaxes are transmitted.

The present invention does not restrict the abovementioned capacitivesensing information, it can be a 2D capacitive sensing information madeup of a plurality of 1D sensing information, or a plurality of linepieces. The above 1D sensing information can be information such as theoriginal value of sensed capacitance, a difference in sensed capacitancebetween adjacent electrodes and/or a dual difference.

To the mainframe 340, these 2D sensing information can be regarded asframes of images. The mainframe 340, upon obtaining these images, canuse various kinds of image processing techniques to carry out subsequentprocesses such as detection of an approaching/touching event,recognition and classification of an approaching/touching event,trajectory tracking of an approaching/touching event, command or textinterpretation after trajectory tracking and the like.

Referring to FIG. 10, a block diagram illustrating a touch processingdevice 330 in accordance with an embodiment of the present invention isshown. The touch processing device 330 includes a transmitter detectingmodule 1010, an information transmitting module 1020, and a capacitivesensing module 1030. The capacitive sensing module 1030 is an optionalmodule, some of its circuits or elements can be shared with thetransmitter detecting module 1010. The present invention does notrestrict the implementation of the touch processing device 330;software, hardware or a combination of the above can be used toimplement the various modules of the touch processing device 330.

The transmitter detecting module 1010 is configured to detect atransmitter that transmits an electrical signal only when approaching ortouching a touch sensitive panel, and generate at least one 2D sensinginformation. The at least one 2D sensing information is a sensinginformation corresponding to a plurality of sensing points with respectto at least one frequency. The information transmitting module 1020 isconfigured to transmit the at least one 2D sensing information.

The optional capacitive sensing module 1030 is configured to detect anexternal conductive object approaching or touching the touch sensitivepanel, and generate a 2D capacitive sensing information. The informationtransmitting module is further configured to transmit the 2D capacitivesensing information. In an embodiment, the 2D sensing information andthe 2D capacitive sensing information are alternately transmitted inwhole. In another embodiment, the 2D sensing information and the 2Dcapacitive sensing information are alternately transmitted in parts.

When the electrical signal is mixed by a plurality of frequencies, thetransmitter detecting module 1010 is configured to generate a pluralityof 2D sensing information, and the information transmitting module 1020is configured to transmit the plurality of 2D sensing information,wherein each frequency corresponds to one of the plurality of 2D sensinginformation, and the number of 2D sensing information generated by thetransmitter detecting module 1010 is larger than or equal to the numberof frequencies included in the electrical signal.

In an embodiment, a first 2D sensing information in the plurality of 2Dsensing information includes a relative value with respect to a second2D sensing information, wherein the relative value is one of thefollowing: a difference, a ratio, and a fractional value.

In an embodiment, each of the plurality of 2D sensing information isalternately transmitted in whole. In an embodiment, each of theplurality of 2D sensing information is alternately transmitted in parts.

In an embodiment, the transmitter transmits the electrical signal onlyin response to detecting a driving signal sent by the capacitive sensingmodule. In some embodiments, the capacitive sensing module allows aplurality of first electrodes on the touch sensitive panel tosequentially send out the driving signal. The 2D sensing information aresensed from a plurality of second electrodes on the touch sensitivepanel. In some other embodiments, the capacitive sensing module allows aplurality of first electrodes on the touch sensitive panel tosimultaneously send out the driving signal. The 2D capacitive sensinginformation and the 2D sensing information are generated according tosignals received in the same period of time.

Referring to FIG. 11, a flowchart illustrating a touch processing methodin accordance with an embodiment of the present invention is shown. Thetouch processing method is applicable to a touch processing deviceconnected to a touch sensitive panel having a plurality of sensingpints. In step 1110, a transmitter that transmits an electrical signalonly when approaching or touching the touch sensitive panel is detected,and at least one 2D sensing information is generated, wherein the atleast one 2D sensing information is a sensing information correspondingto the plurality of sensing points with respect to at least onefrequency. In an optional step 1120, an external conductive objectapproaching or touching the touch sensitive panel is detected, and a 2Dcapacitive sensing information is generated. In step 1130, the at leastone 2D sensing information and the optional 2D capacitive sensinginformation are transmitted. In an embodiment, the 2D sensinginformation and the 2D capacitive sensing information are alternatelytransmitted in whole. In another embodiment, the 2D sensing informationand the 2D capacitive sensing information are alternately transmitted inparts.

When the electrical signal is mixed by a plurality of frequencies, thestep 1110 further includes generating a plurality of 2D sensinginformation. The step 1130 further includes transmitting the pluralityof 2D sensing information, wherein each frequency corresponds to one ofthe plurality of 2D sensing information, wherein the number of 2Dsensing information is larger than or equal to the number of frequenciesincluded in the electrical signal.

In an embodiment, a first 2D sensing information in the plurality of 2Dsensing information includes a relative value with respect to a second2D sensing information, wherein the relative value is one of thefollowing: a difference, a ratio, or a fractional value.

In an embodiment, each of the plurality of 2D sensing information isalternately transmitted in whole. In an embodiment, each of theplurality of 2D sensing information is alternately transmitted in parts.

In an embodiment, the method further includes allowing the touchsensitive panel to send out a driving signal, and the transmittertransmits the electrical signal only in response to detecting thedriving signal. In some embodiments, the method further includesallowing a plurality of first electrodes on the touch sensitive panel tosequentially send out the driving signal. The method further includessensing the 2D sensing information from a plurality of second electrodeson the touch sensitive panel. In some other embodiments, the methodfurther includes allowing a plurality of first electrodes on the touchsensitive panel to simultaneously send out the driving signal. The 2Dcapacitive sensing information and the 2D sensing information aregenerated according to signals received in the same period of time.

In an embodiment, the driving signal simultaneously sent out by theplurality of first electrodes on the touch sensitive panel is used fordetecting if an external object or the transmitter is in proximity tothe touch sensitive panel. The driving signal is sequentially sent outby the plurality of first electrodes on the touch sensitive panel inresponse to detecting an external object or the transmitter in proximityto the touch sensitive panel in order to generate the 2D capacitivesensing information, the at least one 2D sensing information, or both ofthe above.

In summary, one of the main principles of the present invention lies inthat the touch processing device is capable of providing sensinginformation with respect to various frequencies as well as optionalcapacitive sensing information to allow a receiving end to generatevarious kinds of images for subsequent processing using the same touchsensitive panel.

What is claimed is:
 1. A touch processing device connected to a touchsensitive panel, wherein the touch sensitive panel includes a pluralityof first electrodes, a plurality of second electrodes, and a pluralityof sensing points formed at intersections of the plurality of firstelectrodes and the plurality of the second electrodes comprising: atransmitter detecting module, coupled to the plurality of secondelectrodes, for detecting a transmitter that transmits an electricalsignal only in response to a driving signal sent from one of the firstelectrodes of the touch sensitive panel, and generating at least onetwo-dimensional (2D) sensing information, wherein the at least one 2Dsensing information is a sensing information corresponding to theplurality of sensing points with respect to at least one frequency; andan information transmitting module for transmitting the at least one 2Dsensing information; wherein when the electrical signal is mixed by aplurality of frequencies, the transmitter detecting module is configuredto generate a plurality of 2D sensing information, and the informationtransmitting module is configured to transmit the plurality of 2Dsensing information, wherein each frequency corresponds to one of theplurality of 2D sensing information.
 2. The touch processing device ofclaim 1, further comprising: a capacitive sensing module for detectingan external conductive object approaching or touching the touchsensitive panel, and generating a 2D capacitive sensing information, theinformation transmitting module being further configured to transmit the2D capacitive sensing information.
 3. The touch processing device ofclaim 2, wherein the 2D sensing information and the 2D capacitivesensing information are alternately transmitted in whole.
 4. The touchprocessing device of claim 2, wherein the 2D sensing information and the2D capacitive sensing information are alternately transmitted in parts.5. The touch processing device of claim 1, wherein the number of 2Dsensing information generated by the transmitter detecting module islarger than or equal to the number of frequencies included in theelectrical signal.
 6. The touch processing device of claim 1, wherein afirst 2D sensing information in the plurality of 2D sensing informationincludes a relative value with respect to a second 2D sensinginformation.
 7. The touch processing device of claim 6, wherein therelative value is one of the following: a difference; a ratio; and afractional value.
 8. The touch processing device of claim 1, whereineach of the plurality of 2D sensing information is alternatelytransmitted in whole.
 9. The touch processing device of claim 1, whereineach of the plurality of 2D sensing information is alternatelytransmitted in parts.
 10. The touch processing device of claim 2,wherein the transmitter transmits the electrical signal only in responseto detecting the driving signal sent by the capacitive sensing module,the transmitter does not generate the electrical signal when thetransmitter does not detect the driving signal sent by the capacitivesensing module.
 11. The touch processing device of claim 10, wherein thecapacitive sensing module allows the plurality of first electrodes onthe touch sensitive panel to sequentially send out the driving signal,and the at least one 2D sensing information is generated when thecapacitive sensing module is allowing the plurality of first electrodeson the touch sensitive panel to sequentially send out the drivingsignal.
 12. The touch processing device of claim 10, wherein thecapacitive sensing module allows the plurality of first electrodes onthe touch sensitive panel to simultaneously send out the driving signal.13. The touch processing device of claim 11, wherein the 2D sensinginformation is sensed from the plurality of second electrodes on thetouch sensitive panel.
 14. The touch processing device of claim 13,wherein the 2D capacitive sensing information and the 2D sensinginformation are generated according to signals received in the sameperiod of time.
 15. A touch processing method applicable to a touchprocessing device connected to a touch sensitive panel, wherein thetouch sensitive panel includes a plurality of first electrodes, aplurality of second electrodes, and a plurality of sensing points formedat intersections of the plurality of first electrodes and the pluralityof the second electrodes, comprising: detecting, via the plurality ofsecond electrodes, a transmitter that transmits an electrical signalonly in response to a driving signal sent from one of the firstelectrodes of the touch sensitive panel, and generating at least onetwo-dimensional (2D) sensing information, wherein the at least one 2Dsensing information is a sensing information corresponding to theplurality of sensing points with respect to at least one frequency; andtransmitting the at least one 2D sensing information; wherein when theelectrical signal is mixed by a plurality of frequencies, the methodfurther includes: generating a plurality of 2D sensing information; andtransmitting the plurality of 2D sensing information, wherein eachfrequency corresponds to one of the plurality of 2D sensing information.16. The touch processing method of claim 15, further comprising:detecting an external conductive object approaching or touching thetouch sensitive panel, and generating a 2D capacitive sensinginformation; and transmitting the 2D capacitive sensing information. 17.The touch processing method of claim 16, wherein the 2D sensinginformation and the 2D capacitive sensing information are alternatelytransmitted in whole.
 18. The touch processing method of claim 16,wherein the 2D sensing information and the 2D capacitive sensinginformation are alternately.
 19. The touch processing method of claim15, wherein the number of 2D sensing information is larger than or equalto the number of frequencies included in the electrical signal.
 20. Thetouch processing method of claim 15, wherein a first 2D sensinginformation in the plurality of 2D sensing information includes arelative value with respect to a second 2D sensing information.
 21. Thetouch processing method of claim 20, wherein the relative value is oneof the following: a difference; a ratio; and a fractional value.
 22. Thetouch processing method of claim 15, wherein each of the plurality of 2Dsensing information is alternately transmitted in whole.
 23. The touchprocessing method of claim 15, wherein each of the plurality of 2Dsensing information is alternately transmitted in parts.
 24. The touchprocessing method of claim 15, further comprising allowing the touchsensitive panel to send out the driving signal, and the transmittertransmits the electrical signal only in response to detecting thedriving signal, the transmitter does not generate the electrical signalwhen the transmitter does not detect the driving signal.
 25. The touchprocessing method of claim 24, further comprising allowing the pluralityof first electrodes on the touch sensitive panel to sequentially sendout the driving signal, and the at least one 2D sensing information isgenerated when allowing the plurality of first electrodes on the touchsensitive panel to sequentially send out the driving signal.
 26. Thetouch processing method of claim 24, further comprising allowing theplurality of first electrodes on the touch sensitive panel tosimultaneously send out the driving signal.
 27. The touch processingmethod of claim 25, further comprising sensing the 2D sensinginformation from the plurality of second electrodes on the touchsensitive panel.
 28. The touch processing method of claim 27, whereinthe 2D capacitive sensing information and the 2D sensing information aregenerated according to signals received in the same period of time.